images.yandex.com
Search by image in Yandex Searcher, allows to read Cyrillic letters.
LINK: http://images.yandex.com/
imageidentify.com
ImageIdentify is a function in the Wolfram Language that identifies the content of an image.
LINK: http://imageidentify.com/
rootabout.com
You supply a picture, and RootAbout will check if it looks similar to any indexed picture. For pictures that match, RootAbout provides additional information about the picture and a link to where you can find more information.
LINK: http://rootabout.com/
online-barcode-reader.inliteresearch.com
Allow to reading product, QR and document barcodes.
LINK: http://online-barcode-reader.inliteresearch.com/
images.google.com
Search by image in Google Searcher.
LINK: http://images.google.com/
bing.com/images
Search by image in Bing Searcher.
LINK: http://bing.com/images
graph.baidu.com
Search by image in Chinese Baidu Browser, allows to read Asian letters.
LINK: http://graph.baidu.com/
taringa.net/search/story
Search engine for Taringa Images (Spanish Social Network).
LINK: https://www.taringa.net/search/story?q=%253CSEARCH%2520TERM%253E&sort=recent&nsfw=false
ccsearch.creativecommons.org
Here you can find images to use and remix across several open archives.
twipho.net
TwiPho is a Twitter photo search engine. It can find twitpic.com, img.ly and yfrog.com images embedded into Tweet.
LINK: http://twipho.net/